Universal coupler

ABSTRACT

A universal coupler for coupling multiple orthopedic instruments is disclosed. The universal coupler includes a body having a boss and an internal bore, a locking shaft having a first portion and a second portion, a trigger including a trigger bore, and a connection portion. The trigger is operable between a first position and a second position, where in the first position the first portion and boss are misaligned and in the second position the first portion and the boss are aligned.

FIELD OF THE INVENTION

The present invention relates to the assembly or mating of surgicalinstruments, and more particularly, to a quick connect universal couplerfor allowing the temporary coupling of multiple surgical instruments.

BACKGROUND OF THE INVENTION

Many surgical procedures require the use of orthopedic instruments andancillary instruments, such as resection guides, gauges, trackingdevices, and positioning apparatus. Often times, these variousinstruments are interactive and need to be assembled and disassembledwith each other, thereby requiring some sort of assembly during thesurgical procedure. For example, total knee arthroplasty instrumentationfrequently requires the use of locating styli or navigation trackers toproperly align resection guides. These positioning tools must typicallybe removably attached to their respective resection guides, to allow forboth easy insertion and proper use of the resection guides duringsurgery.

There have been many attempts at designing coupling means to assembleancillary instruments, such as tibial and femoral styli, to theircounterpart instrument (e.g.—resection guides) during surgery. Thesemeans include threaded designs, ball plunger designs and tongue andgroove designs. However, problems exist with each of these designs.Threaded designs take significant time to align, turn, and lock.Additionally, applying adequate locking torque to a relatively smallscrew head is difficult to do with slippery gloves. Ball plunger designsare not ergonomic to use, as they are generally designed to be activatedfrom the top by compressing a spring loaded release button with thethumb, while holding and stabilizing the instrument with the index andmiddle fingers. If the ancillary instrument is being attached to aninstrument already secured to the bone, operating a ball plungerrequires the hand to be forced into a partially supinated position thatis not optimum from an ergonomic stand point. Finally, tongue and groovedesigns are used primarily in tibial cutting guides where a slot usedfor the saw blade is already present. This design is thus limited toinstruments that may not be able to accommodate a slot due to sizeand/or shape constraints.

For the foregoing reasons, there exists a need for a coupler orconnector that is quick and easy to utilize.

SUMMARY OF THE INVENTION

A first aspect of the present invention is a universal coupler. Theuniversal coupler according to this aspect includes a body including aboss and an internal bore, a locking shaft including a first portion anda second portion, the second portion disposed within the internal boreof the body, a trigger including a trigger bore for receiving the secondportion of the locking shaft, and a connection portion connected to thebody for facilitating the connection of the universal coupler to anancillary instrument. The actuation of the trigger from a first positionto a second position moves the locking shaft from a first position inwhich the locking shaft is misaligned from the boss, to a secondposition in which the locking shaft is aligned with the boss.

Another embodiment of the present invention is another universalcoupler. The universal couple according to this embodiment includes aboss including an internal bore, the boss having a first axis and theinternal bore having a second axis, the first axis and second axis beingparallel and spaced apart a first distance; a locking shaft including afirst portion and a second portion, the first portion having a thirdaxis and the second portion having a fourth axis, the third axis andfourth axis being parallel and spaced apart a second distance, thesecond portion disposed within the internal bore of the boss and thefirst distance equal to the second distance; and a trigger assemblyincluding a trigger, the trigger having a trigger bore for receiving thesecond portion of the locking shaft. The trigger is movable between afirst position and a second position, the first position causing theboss and the locking shaft to be misaligned and the second positioncausing the boss and the locking shaft to align.

Yet another embodiment of the present invention is a coupling system forconnecting two parts. The system includes a first part having a borehaving an end open to an enlarged portion forming a shoulder between thebore end and the enlarged portion, a second part having a cannulatedshaft having an outer surface sized to be received within the bore inthe first part, the cannulation in the shaft extending along an axisoffset from at least a portion of the outer shaft surface; and a lockingelement rotatably received within the cannulation, the locking elementhaving a first end with an actuator coupled thereto for rotating thelocking element within the second part and a second end having aradially extending flange, the flange having portions spaced from theaxis of the cannulation a distance such that rotation of the lockingelement with the actuator moves the flange from a first position whereinthe flange extends beyond a portion of the shaft outer surface intoengagement with the shoulder of the first part to connect the first andsecond parts to a second position wherein the flange is aligned withinthe shaft outer surface to allow insertion or removal of the shaft fromthe bore in the first part.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be better understood on reading the followingdetailed description of non-limiting embodiments thereof, and onexamining the accompanying drawings, in which:

FIG. 1 is a top perspective view of the universal coupler according toan embodiment of the present invention with its trigger in a firstposition.

FIG. 2 is a top perspective view of the universal coupler according toFIG. 1 with its trigger in a second position.

FIG. 3 is a side view of the universal coupler according to FIG. 2 withinternal structure being in phantom.

FIG. 4 is a top cross sectional view of section A-A of FIG. 3.

FIG. 5 is a side perspective view of the locking shaft according to FIG.1.

FIG. 6 is a top cross sectional view of section B-B of FIG. 3.

FIG. 7 is a top view of the universal coupler according to FIG. 1.

FIGS. 8 a-8 d depict the universal coupler according to variousembodiments of the present invention having different connectionportions and connected to different instruments.

FIG. 9 is a front cross sectional view of the present inventiondepicting the connection between the universal coupler of FIG. 1 andanother instrument.

FIG. 10 is a side view of the universal coupler according to anotherembodiment of the present invention.

DETAILED DESCRIPTION

In describing the preferred embodiments of the subject matterillustrated and to be described with respect to the drawings, specificterminology will be resorted to for the sake of clarity. However, theinvention is not intended to be limited to the specific term andincludes all technical equivalence which operates in a similar manner toaccomplish a similar purpose.

Referring to the drawings, wherein like reference numerals representlike elements, there is shown in the Figures, in accordance withembodiments of the present invention, a universal coupler designatedgenerally by reference numeral 10. In the embodiment shown in theFigures, coupler 10 is designed to be used in coupling at least two andpreferably multiple instruments together in order to perform surgery.For example, as shown in FIGS. 8 a-8 d respectively, coupler 10 may beused in coupling a patella caliper to a single jaw of a patellaresection guide, a navigation tracker adapter to a tibial alignmenthandle, a femoral stylus to an anterior posterior femoral resectionguide, and tibial stylus to a tibial resection guide. While certaininstruments are specifically shown being coupled by coupler 10, it isnoted that any combination of instruments may be assembled together. Asshown in the Figures, coupler 10 includes body 12, cylindrical boss orshaft 14, locking shaft or flange 16, trigger or actuator 18, andconnection portion 20.

The preferred body 12, as shown in the Figures is substantiallyrectangular, but may be any shape. Cylindrical boss 14 is asubstantially circular tube extending from body 12, and like that ofbody 12 may be any shape, the only requirement being that its shape mustcorrespond to a hole which it is inserted into. This will be furtherdiscussed below. In the embodiment shown in FIGS. 1 and 2, body 12 andcylindrical boss 14 are a single unitary body. However, it iscontemplated that other embodiments may include separately constructedpieces that are thereafter mated together by such techniques as welding.As best shown in FIG. 1, body 12 includes main housing 22 and recessedportion 24. Recessed portion 24 is adapted to receive trigger oractuator 18. This will be discussed further below. Further, body 12 alsoincludes internal bore 26 (best shown in FIG. 2) and spring assembly 28.In the preferred embodiment, internal bore or cannulation 26 extendsthrough the entire unitary form created by body 12 and cylindrical boss14, thus extending through recessed portion 24, main housing 22, andcylindrical boss 14. Internal bore 26 is eccentrically located to acenter axis of cylindrical boss 14. As is best shown in FIG. 3, springassembly 28 includes spring 30 and plunger 32, both of which are housedwithin counter bore 34. The operation of spring assembly 28 will bediscussed below.

In the preferred embodiment locking shaft 16 includes a firstcylindrical portion 36 and a second cylindrical portion 38. This is bestshown in FIG. 4. First and second cylindrical portions 36 and 38 areformed integral with one another, however, it is contemplated that theymay be formed separately and attached thereafter. First cylindricalportion 36 is typically the same shape and has substantially the samediameter as cylindrical boss 14. Second cylindrical portion 38 issubstantially circular, with a diameter slightly smaller than that ofinternal bore 26. Second cylindrical portion 38 is arranged eccentric toa center axis of first cylindrical portion 36. The distance secondcylindrical portion 38 is offset from the center axis of firstcylindrical portion 36 is substantially equal to the distance whichinternal bore 26 is offset from the center axis of cylindrical boss 14.Upon assembly of locking shaft 16 with the remainder of the elements ofcoupler 10, second cylindrical portion 38 is placed into and throughinternal bore 26. The cooperation between second cylindrical portion 38and cylindrical boss 14 is depicted in the cross sectional view of FIG.5.

As is best shown in FIG. 3, trigger or actuator 18 is a substantiallyU-shaped member designed to fit within recessed portion 24 of body 12.However, it is contemplated that trigger 18 may be of any shape. Trigger18 includes trigger bore 40, which is configured and sized to receivethe portion of second cylindrical portion 38 that extends throughinternal bore 26. Essentially, the connection between second cylindricalportion 38 and trigger bore 40 fixably mounts body 12, boss 14, andlocking shaft 16 of coupler 10 to one another, while also allowing forthe rotation of trigger 18 and second cylindrical portion with respectto body 12.

The assembly of locking shaft 16 and trigger 18 to body 12 and boss 14should be such that when trigger 18 is in a first position, lockingshaft 16 is misaligned from boss 14. This first position is depicted inFIG. 1. The eccentric arrangement of second cylindrical portion 38 withrespect to first cylindrical portion 36 allows for the misalignment oflocking shaft 16 and boss 14. Essentially, trigger 18 is placed in itsfirst position and attached to locking shaft 16 while the locking shaftis rotated with respect to boss 14. The aforementioned spring assembly28 is designed and positioned to provide a constant force to trigger 18and cause the trigger to remain in this first position, absent some sortof counteracting force. Upon application of a counteracting force,trigger 18 is rotated, along with second cylindrical portion 38, into asecond position, in which locking shaft 16 and boss 14 are aligned. Thisposition is best shown in FIG. 2.

Connection portion 20 is connected to recessed portion 24 of body 12. Asshown in the Figures, connection portion 20 is formed integral with body12, thus, boss 14, main housing 22, recessed portion 24, and connectionportion 20 make up a single unitary body. However, it is contemplatedthat each element may be formed separately, and thereafter attached toone another. Connection portion 20, as shown in the Figures, is designedand configured to receive and hold a stylus 42. In the embodiment shown,connection portion 20 is substantially rectangular with one roundedside, and includes reception hole 44, bore 46, and spring loaded balldetent 48. Reception hole 44 is adapted to receive a portion of stylus42, and ball detent 48 is adapted to apply a force thereto to holdstylus 42 in place. In other embodiments, connection portion 20 mayinclude a set screw bore and set screw. In these embodiments, the setscrew is adapted, when tightened in the set screw bore, to hold stylus42 in place. It is contemplated that various other instruments may beconnected to coupler 10 by connection portion 20. It is alsocontemplated that connection portion 20 can be various configurations inorder to accommodate the attachment of different instruments. Forexample, FIG. 7 a-7 d show different connection portions 20 forreceiving and holding different instruments.

Another aspect of the present invention is a method of coupling anancillary instrument to an orthopedic instrument. The method accordingto this aspect of the present invention includes the step of providing auniversal coupler as discussed above. It is noted that the coupler canbe in accordance with any of the various embodiments disclosed herein,as the particular design may not cause the standard method steps tosignificantly deviate. For the sake of ease in explaining the method,coupler 10 will be utilized herein. The method according to this aspectof the present invention also includes the step of providing aninstrument having a mating hole sufficient for receiving coupler 10,such as resection guide 60, as well as an ancillary instrument such asstylus 42.

In another step according to the method, stylus 42 or other ancillaryinstrument is attached to coupler 10. It is contemplated that this stepmay be performed prior or subsequent to connecting coupler 10 to anorthopedic instrument. In one preferred embodiment, stylus 42 isconnected to coupler 10 prior to attachment of coupler 10 to resectionguide 60. In order to connect stylus 42 to coupler 10, a portion of thestylus is inserted into reception hole 44, where ball detent 48 isdisposed to hold stylus 42 in place. With stylus 42 attached to coupler10, trigger 18 is depressed, thereby aligning locking shaft 16 with boss14 and creating a continuous tubular shaft. This continuous shaft isinserted into a mating hole 50 of resection guide 60, until lockingshaft 16 extends beyond hole 50. Thereafter, the continuous forceapplied to depress trigger 18 is ceased and spring assembly 28 causestrigger 18 to return to its first position. This in turn causes lockingshaft or flange 16 and boss 14 to become misaligned, and coupler 10,along with stylus 42, is coupled to resection guide 60. In a preferredembodiment, the preferred offset is approximately 0.042 inches, and therotation necessary to align flange 16 and boss 14 is approximately 30degrees. However, it is contemplated that these dimensions can vary indifferent embodiments. As shown in FIG. 8, coupler 10 includes boss 14having a diameter D1 and a length L1. Mating hole 50 has a diameter D2and a length L2. It the embodiment shown, D1 is slightly less than D2and L1 is slightly longer than L2. This allows for the solid and sturdyconnection between the coupler and the instrument.

FIG. 9 shows another embodiment of the present invention, universalcoupler 110. Coupler 110 is substantially similar to coupler 10, exceptfor a different connection portion 120 and the inclusion of rotationlocking element 122. Connection portion 120 is configured to allow forthe connection and vertical positioning of ancillary instrument 124.Ancillary instrument 124 is a height or thickness gauge for measuringthe thickness of a patella, but may be any other type of instrument.Locking element 122 is hexagonal extension extending from body 112 andconnected to boss 114. Locking element 122 is designed to fit within acorresponding hexagonal aperture located around a mating hole similar tomating hole 50 discussed above. Upon insertion of coupler 110 into themating hole having a hexagonal aperture, locking element 122 engages thehexagonal aperture. While the misalignment of locking shaft 116 and boss114 only prevents removal of coupler 110 from the mating hole, thelocking element 122 and hexagonal aperture relationship also prevent therotation of coupler 110. This is desired in certain situations whereboth coupling and rotation locking are required. It is contemplated thatin other embodiments, locking element 122 may be any shape suitable forpreventing rotation of coupler 110. The only requirement being thatlocking element 122 be configured to mate with a corresponding matinghole. It is also contemplated that rather than including locking element122, boss 114 and locking shaft 116 may be shaped in order to similarlyprevent rotation.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A universal coupler comprising: a body including a boss having aninternal bore therethrough; a locking shaft including a first portionand a second portion, the first and second portions integrally formedwith each other, the second portion disposed within the internal bore ofsaid body; a trigger rotatably mounted relative to said body andincluding a trigger body having a bore receiving and rotatably fixingsaid trigger to the second portion of said locking shaft and a portionextending therefrom; a spring connected to said body biasing saidextending portion of said trigger such that said trigger remains in afirst, locking position; and a connection portion connected to said bodyfor facilitating the connection of said universal coupler to anancillary instrument, wherein actuation of said trigger from said first,locking position to a second, unlocking position rotates the first andsecond portions of said locking shaft from a first position in whichsaid first portion is misaligned from said boss, to a second position inwhich said first portion is aligned with said boss.
 2. The universalcoupler of claim 1, wherein the boss and the first portion aresubstantially the same shape.
 3. The universal coupler of claim 2,wherein the boss and the first portion are substantially cylindrical. 4.The universal coupler of claim 1, wherein the internal bore and thesecond portion are substantially the same shape.
 5. The universalcoupler of claim 4, wherein the internal bore and the second portion aresubstantially cylindrical.
 6. The universal coupler of claim 1, whereinthe boss has a first central axis, the internal bore has a secondcentral axis, the first portion has a third central axis, and the secondportion has a fourth central axis, the first central axis and the secondcentral axis are parallel and spaced apart a first distance, and thethird central axis and fourth central axis are parallel and spaced aparta second distance, the first and second distances being equal.
 7. Theuniversal coupler of claim 1, wherein actuation of said trigger causesthe first central axis and the third central axis to be coaxial.
 8. Theuniversal coupler of claim 7, wherein the boss and the first portion arecylindrical and have substantially equal diameters.
 9. The universalcoupler of claim 7, wherein the boss and the first portion arenon-cylindrical.
 10. The universal coupler of claim 7, wherein saidtrigger is biased to cause the first central axis and the third centralaxis to be askew.
 11. The universal coupler of claim 1, wherein saiduniversal coupler is constructed from a metallic material.
 12. Anassembly, wherein an instrument is connected to the universal coupler ofclaim
 1. 13. The assembly of claim 12, wherein said instrument is aresection guide.
 14. The assembly of claim 12, wherein said instrumentis a stylus.
 15. The universal coupler of claim 1, further comprising alocking element for the prevention of rotation.
 16. The universalcoupler of claim 15, wherein the locking element is non-circular. 17.The universal coupler of claim 16, wherein the locking element ishexagonal.
 18. A universal coupler comprising: a boss including aninternal bore, said boss having a first central axis and the internalbore having a second central axis, the first central axis and secondcentral axis being parallel and spaced apart a first distance; a lockingshaft including a first portion and a second portion, the first portionhaving a third central axis and the second portion having a fourthcentral axis, the third central axis and fourth central axis beingparallel and spaced apart a second distance, the second portion disposedwithin the internal bore of said boss; a trigger assembly rotatablymounted relative to said boss comprising: a trigger body, having atrigger bore receiving and rotatably fixing said trigger to the secondportion of said locking shaft, a portion extending from said triggerbody, and a spring assembly biasing said extending portion of saidtrigger such that said trigger remains in a first, locking position; andwherein the trigger is movable between said first, locking position anda second, unlocking position, the first position causing the firstcentral axis of said boss and the third central axis of said firstportion to be askew and the second position causing the first centralaxis of said boss and the third central axis of said first portion to becoaxial.
 19. The universal coupler of claim 18, wherein said springassembly further includes a spring plunger.
 20. The universal coupler ofclaim 18, wherein the first distance is equal to the second distance.21. The universal coupler of claim 18, wherein said boss and the firstportion are substantially the same shape.
 22. The universal coupler ofclaim 21, wherein the boss and the first portion are substantiallycylindrical.
 23. The universal coupler of claim 18, wherein the internalbore and the second portion are substantially the same shape.
 24. Theuniversal coupler of claim 23, wherein the internal bore and the secondportion are substantially cylindrical.
 25. The universal coupler ofclaim 18, further comprising a connection portion.
 26. The universalcoupler of claim 18, wherein actuation of said trigger assembly causesrotation of the first and second portions.
 27. The universal coupler ofclaim 18, wherein the boss and the first portion are cylindrical andhave equal diameters.
 28. The universal coupler of claim 18, whereinsaid trigger remains in the first position absent a force.
 29. Theuniversal coupler of claim 18, wherein said universal coupler isconstructed from a metallic material.
 30. An assembly, wherein aninstrument is connected to the universal coupler of claim
 18. 31. Theassembly of claim 30, wherein said instrument is a resection guide. 32.The assembly of claim 30, wherein said instrument is a stylus.
 33. Theuniversal coupler of claim 18, further comprising a locking element forthe prevention of rotation.
 34. The universal coupler of claim 33,wherein the locking element is non-circular.
 35. The universal couplerof claim 33, wherein the locking element is hexagonal.
 36. A couplingsystem for connecting two parts, said system comprising: a first parthaving a first bore having an end open to an enlarged portion forming ashoulder between said first bore end and said enlarged portion; a secondpart having a shaft having a second bore and an outer surface sized tobe received within said first bore in said first part, said second borein said shaft extending along an axis offset from at least a portion ofsaid outer shaft surface; and a locking element rotatably receivedwithin said second bore, said locking element having a first end with abiased actuator coupled thereto for rotating said locking element withinsaid second part and a second end having a radially extending flange,said flange having portions spaced from the axis of said second bore adistance such that rotation of said locking element with said actuatormoves said flange from a first position wherein said flange extendsbeyond a portion of said shaft outer surface into engagement with saidshoulder of said first part to connect said first and second parts to asecond position wherein the flange is aligned within said shaft outersurface to allow insertion or removal of said shaft from said first borein said first part wherein said locking element is biased towards saidfirst position.
 37. The coupling system as set forth in claim 36 whereinsaid biasing is provided by a coil spring acting on said actuator. 38.The coupling system as set forth in claim 36 wherein said lockingelement is a rod and said flange is circular and coupled to an end ofsaid rod wherein a central axis of the rod is offset from a central axisof the flange.
 39. The coupling system as set forth in claim 38 whereinsaid shaft is circular and wherein the axis of said second bore in saidshaft is offset from a central axis of said circular shaft.
 40. Thecoupling system as set forth in claim 39 wherein said shaft is rotatablewithin said first bore.
 41. The coupling system as set forth in claim 40further comprising means for rotationally locking said shaft within saidfirst bore.
 42. The coupling system as set forth in claim 36 whereinsaid enlarged portion is a bottom surface of a plate.
 43. The couplingsystem as set forth in claim 36 wherein said flange has portions spacedfrom said second axis a distance equal to the offset between said axisand said portion of said shaft outer surface.